Worked on security hardening for Android file saving in the ionic-team/capacitor repository, focusing on preventing directory traversal vulnerabilities. Addressed a bug by implementing sanitization of portable file names, replacing potentially harmful characters and path segments with underscores to ensure files are saved only to intended directories. This approach reduced the risk of path traversal attacks across Capacitor-based Android applications while maintaining backward compatibility and minimizing potential regressions. The work leveraged Java for Android development, with a strong emphasis on secure file handling practices. The solution improved the overall security posture of file operations without introducing breaking changes or disrupting existing workflows.